In order to ensure the timely completion of the above-mentioned terminal installation tasks, the ministry of transport and communications issued a circular specifying that, as of 1 january 2013, "two at-risk" vehicles in use in the model provinces (long-distance passenger buses, tourist buses and dangerous cargo carriers) should be upgraded with a beidou compatible terminal; all newly entered transport markets should be equipped with a beid-compatible vehicle terminal and access to a public control and service platform for road cargo vehicles; and rural passenger vehicles should be encouraged to install a beidong-compatible end. Since 1 june 2013, all new "two-passenger" vehicles entering the transport market in the model provinces, as well as heavy cargo vehicles and semi-trailers, should be equipped with a beidou-compatible vehicle terminal before the vehicle leaves the factory. Road transport permits will not be issued or reviewed for vehicles that do not install or install beidou compatible vehicle terminals as required. The beidou navigation system aims to provide high-quality positioning, navigation and timing services to global users, including both open and authorized services. The open service is a location, speed and timing service that is provided free of charge globally, with a positioning accuracy of 10 metres, a speed accuracy of 0. 2 metres/s and a time accuracy of 10 ns. The mandated service is to provide positioning, speed measurement, timing and communication services and system integrity information for users with high-precision, high-reliability satellite navigation needs. Beyond europe and the united states, the beidou satellite navigation system solves the question of who, when and where, that is, the beidou feature service, which you can travel through the world with a beidou terminal. The services provided worldwide are free of charge, and in providing services such as passive positioning navigation and timing, the number of users is unlimited and compatible with gps; they are particularly suitable for large-scale monitoring and management by group users, as well as for data transfer applications for data acquisition in untrusted areas; unique central location processing and command-type user devices are designed to address "where am i?" and "where are you?"; and autonomous systems, high-intensity encryption designs, secure, reliable, stable and suitable for critical sector applications。